Thermal stability of poly(acryloyl chloride) homopolymer and copolymers of acryloyl chloride with methyl methacrylate

The thermal stabilities of poly(acryloyl chloride) homopolymer and copolymers of acryloyl chloride with methyl methacrylate covering the entire composition range were studied by thermogravimetric analysis. At each extreme of the composition range incorporation of comonomer units results in a copolymer which is less stable than the PMMA homopolymer. The activation energies of the decomposition of the copolymers were calculated using the Arrhenius equation and found to decrease from 32.2 to 12.5 kJ mol^?1 as acryloyl chloride concentration of the copolymer increases, indicating that the copolymers of higher acryloyl chloride concentration should easier decompose than other copolymers. The reactivity ratios of the copolymer were calculated and found to ber ₁(AC)=0.2±0.02 andr ₂(MMA)=0.9±0.1.     

Synthèses en une seule etape de nouvelles molécules heptacycliques à partir de sels de 2-aryl-4-méthyl-1-benzopyrylium. Structures radiocristallographiques de composés renfermant le squelette d'une 1-benzoxépine methano-pontée et condensée à deux entités de 1-benzopyrane

One-Step Synthesis of Novel Heptacyclic Molecules Starting from 2-Aryl-4-methyl-1-benzopyrylium Salts. X-Ray Crystal Structures of These Compounds Containing a Methano-Bridged 1-Benzoxepine Fused to Two 1-Benzopyran Moieties The chemical reduction of 4-methyl-2-(ortho-hydroxyaryl)-1-benzopyrylium chlorides with Zn in MeCN and HCl led to a mixture of diastereoisomeric heptacyclic molecules. The structures of two of them were determined by X-ray analysis. These methano-bridged 1-benzoxepines fused to two 1-benzopyran moieties were formed from intermediate biflavene species.     

关于K个复相关矩阵相等的检验

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Study of theS-matrix near bound states in the continuum

The behaviour ofS-matrix for potentials generating bound states in continuum in the neighbourhood of the positive bound state energies is studied. It is shown that unlike the case of usual negative energy bound states, theS-matrix does not have a pole at the positive bound state energy but becomes unity at the energy corresponding to bound states in continuum. Calculations ofS-waveS-matrix for a local potential constructed by Stillinger and Herrick and a separable nonlocal potential constructed by the present authors verify these results. Our results indicate that the bound states embedded in continuum constructedvia the von Neumann and Wigner procedure cannot be interpreted as resonances with zero width.     

Synthesis,spectroscopic, thermal properties,Calf thymus DNA binding and quantum chemical studies of M(II) complexes

A new series of transition metal complexes of Cu(II), Co(II), Ni(II), Mn(II) and Cd(II) were prepared from the ligand of 5‐(4‐benzenesulfonic acid azo)‐2‐thioxo‐4‐thiazolidinone (H₂L). The M(II) complexes were structurally elucidated by elemental analysis, infrared spectra, spectral studies, thermal analysis, magnetic measurements and X‐ray diffraction analysis. Elemental analysis and IR result suggested the ligand was bonded to the metal ions in monobasic/neutral bidentate through the nitrogen atom of the hydrazone group and oxygen atom of carbonyl group. The bond length, bond angle, HOMO, LUMO and quantum chemical parameters were calculated to confirm the geometry of the ligand and the M(II) complexes. In vitro antimicrobial behavior of ligand (H₂L) and its M(II) complexes (1‐5) was screened with targeted bacterial and fungal strains. Spectroscopic (UV‐vis) technique was employed in order to study the binding mode and binding strength of the ligand (H₂L) and its M(II) complexes to Calf thymus DNA (CT‐DNA). Intercalation is the most possible mode of interaction of the ligand (H₂L) and its M(II) complexes with CT‐DNA and the determined binding constants. Molecular docking was used to predict the binding between the starts (4‐aminobenzenesulfonic acid (start 1) and 2‐thioxo‐4‐thiazolidinone (start 2)) and tautomers (A‐C) of ligand (H₂L) with the receptors of prostate cancer mutant (PDB code: 2Q7K) and breast cancer mutant (PDB code: 3HB5).     

Polymer complexes. LXIX. Some divalent metal(II) polymer complexes of potentially bidentate monomer N‐[4‐(5‐methyl‐isoxazol‐3‐ylsulfamoyl)‐phenyl]‐acrylamide: Synthesis,spectroscopic characterization,thermal properties,antimicrobial agents and DNA studies

Monomer of N‐[4‐(5‐methyl‐isoxazol‐3‐ylsulfamoyl)‐phenyl]‐acrylamide (HL) and some transition metal polymeric complexes of the general formula {[M(HL)(OH₂)₂(OCOCH₃)₂] xH₂O}_n (M = Co(II), x = 2; Ni(II), x = 3; Mn(II), x = 2) and [Cd(HL)₂(OCOCH₃)₂] were synthesized and characterized by elemental analysis, IR, UV spectroscopy, conductance measurements, magnetic susceptibility, thermogravimetric analyses and X‐ray diffraction analysis. In all polymer complexes, the spectral data revealed that the ligand act as bidentate neutral molecule and coordinate to metal ion through enolic sulphonamide OH and isoxazol‐N. In all polymer complexes, the spectral data revealed that the ligand act as bidentate neutral molecule and coordinate to metal ion through enolic sulphonamide OH and isoxazol‐N. The molar conductance data revealed that the polymer complexes are non‐electrolytes while UV‐vis and magnetic measurements data have been shown that the polymer complexes have octahedral geometry. All the studies revealed coordination six for the metals in all the polymer complexes and octahedral structures were suggested. The inhibitive effect of HL against C38 steel was investigated in 2 M HCl solution (tafel polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) methods). The type of HL is mixed inhibitor whose adsorption habit onto C38 steel.     

The Reaction of Ketenylidenetriphenylphosphorane (Ph3P˭C˭C˭O) with Acidic H‒E (E˭O,N) Bonds

Abstract

The reactivity of ketenylidenetriphenylphosphorane (1) with the protic reagents 2,4,6-trimethylphenol (7), 2,6-di-tert-butyl-4-methylphenol (8), and diphenylamine (9) has been explored. Three novel carbonyl-stabilized ylides have been synthesized and characterized. Crystal structures were obtained for Ph₃PCHC(O)O(C₆H₂Me₃) (11), Ph₃PCHC(O)O(C₆H₂t-Bu₂Me) (12), and Ph₃PCHC(O)NPh₂ (13), respectively. These products were then methylated in an attempt to develop a new route to low-valent carbon compounds. Crystals of [Ph₃PCH(CH₃)C(O)O(C₆H₂Me₃)]I (14) were isolated and characterized but this route did not prove to be synthetically useful, at least toward the goal of preparing low-valent carbon-centered materials. Finally, 1 was also reacted with the bulky tin reagent, bis[bis(trimethylsilyl)amido]tin(II), in the presence of 2,4,6-trimethylphenol. A complex mixture of products was obtained, from which crystals of an unusual chelated tin compound (15) were isolated and characterized using X-ray crystallography.